Evidence for viable, non-clonal but fatherless Boa constrictors

Area of Science:

• Evolutionary Biology
• Reproductive Biology
• Herpetology

Background:

• Parthenogenesis is a rare reproductive mode in vertebrates.
• In snakes (ZZ:ZW sex chromosomes), viable WW female offspring have not been naturally produced.
• Previous WW female production in vertebrates required experimental manipulation (fish, amphibians).

Purpose of the Study:

• To investigate facultative parthenogenesis in Boa constrictors.
• To provide the first evidence of naturally produced, viable WW females in a snake species.
• To explore the prevalence of parthenogenesis in basal reptilian lineages.

Main Methods:

• Microsatellite DNA fingerprinting was used to analyze parentage.
• Non-experimentally induced offspring from a Boa constrictor were examined.
• Genetic analysis focused on sex chromosomes and homozygosity.

Main Results:

• The first evidence of facultative parthenogenesis in a Boa constrictor was found.
• Multiple viable, non-experimentally induced female offspring were identified.
• Offspring exhibited elevated homozygosity, suggesting terminal fusion automixis.
• No male offspring were produced, potentially indicating WO sex chromosomes.

Conclusions:

• This study presents the first natural parthenogenesis resulting in viable WW females in any vertebrate.
• Parthenogenesis is documented for the first time in the family Boidae (Boas).
• WW females may be more common in basal reptilian lineages than previously assumed.